Underreamer.



R. E. BOLE. UNDERRBAMER. APPLIOATION FILED F}:B 19, 1913.

Patented Dec. 2, 1913.

IIL 4m.

u TED sauras ROBERTE. BOLE, OF LOS ANGELES, CALIFORNIA, ASSIGNGR 0F ONE-HALF TO EDWARD DOUBLE, 0F LOS ANGELES, CALIFORNIA.

UNDERREAMER.

To all whom it may concern Be it kno-wn that I, ROBERT E. Bonn, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Underreamer, of which the following is a speciiication.

This invention relates to an improvement in underreamers and has for its particular object, the provision of a simple and exceedingly durable mo-unting of the spring actuated rod or mandrel within and on the body of the underreamer.

The invention consists in the constructions and combinations of parts. hereinafter described and more particularly pointed out in the claims, and will be more readily understood by the accompanying drawings in which: l

Figure l is a side view of an underreamer' embodying my invention, the underreamer being shown as projecting just below the shoe of a well casing and a portion of the upper end of the body of the reamer and well casing being omitted, the spring actuated rod or mandrel and bits being shown in dotted lines in expanded or underreaming position. Fig. 2 is a similar longitudinal sectional view showing the underreamer within the well casing and the bits in collapsed position. Fig. 3 is a partial longitudinal sectional -view of the body of the underreamer. Fig. 4 is a sectional view on the line m4-m4 of Fig. 5 of the spring actuated rod or mandrel, and showing the key or gib in dotted lines. Fig. 5 is a side View of the spring actuated rod or`mandrel,a portion of the coil spring being indicated thereon. Fig. 6 is a cross sectional view on the line :11G-m6 of Fig. 4 showing the relation of the coil spring and themandrel or spring actuated rod. Fig. v7 is a perspective View of the key or gib.

In the type of underreamers illustrated, for example, in the patent to Vilson, No. 827,595, dated July 31st,` 1906, the spring actuated rod or mandrel upon which the underreamer cutters or bits are carried, is shown as held in the center bore of the body portion of the underreamer by means of dowel-p-ins. Such construction was found in actual practice to be weak and liable Y'to break, leaving the cutters and spring actu.

ated rod. or mandrel in the well hole. To obviate thls wealmess I provide the body lpor- Specication of Letters Patent.

tion 2 above the upper ends of the bits 3 with a slot 4 and correspondingly slot the mandrel or spring actuated rodhl as at 5. Through these slots I project a gib or key 6, the outer ends of the key or gib resting upon the bottom walls of the slots in the body portion and seating thereon.. The slot 5 in the spring actuated rod or mandrel 13 is made of sufficient length to permit the necessary or desired reciprocation of the rod or mandrel in the body of the reamer, and in order to secure the proper tension on the spring 7 surrounding such rod or mandrel, I seat the lower end of the spring upon this gib or key and the upper end of the spring is compressed to a suitable degree by means of a' nut 8 threaded onto the upper end of the sprin actuated rod or mandrel. By adjusting t is nut the tension of the spring and consequently the upward throw o-f the mandrel o r rod in the body of the'reamer may be regulated at will. This gib or key 6 is loosely mounted in the slot 4 of the mandrel or body, that is to say, it is not attached to said body by any means which mechanically IiX it as a part of such body. The tension of the coiled spring 7 'holds this key or gib 6 in position so that the wing or downwardly projecting portion 11 seats in the bore 12 of the body and the gib is so proportioned as to permit the passage thereof laterally 'through the Slo-t 4 after the wing or projection 11 has been raised out' o-f the lower extension of the bore l2. The lower end of this spring actuated rod or mandrel may be provided with wings or prongs 9 forming an integral T-head on which the bits 3 are mounted and tilt or move pivotally. In place of forming this T-head integral with the spring actuated rod, I may provide a slot (not shown) through the rod and utilize a removable key or gib, the ends of which seat in the sockets or key-seats 10 of the bits or cutters. The sockets or keyseats l0 of the bits are preferably somewhat larger than the wings 9, to permit of the necessary tilting action. The gib or key 6 is preferably provided with a wing or downwardly projecting portion 11 of sufficient width to just t within the bore 12 of the vbody 2 and thus prevent the accidental dis- Patented Dec. 2,1913.

pplication led February 19, 1913. Serial No. 749,343.

upper ends of the bits. Below the slot 4 in the body portion I leave suflicient metal to provide strong seats for the key or gib 6 and below such seats the body p'ortion is formed in a hollow slotted extension 15, the side walls off the slot at each side being provided with dovetails 1G adapted to coact with corresponding dovetails on the bits, as shown in said patent to Wilson.

I claim:

1. An underreamer comprising a body having a central bore, a rod or mandrel mounted in said bore, said body provided with a slot, said rod provided with a longitudinal slot, a key or gib mounted in said slot and provided with a downwardly prol jecting portion adapted to contact with the wall of the central bore below said slot and prevent lateral displacement of the key from either side of the slot, a spring mounted on said gib and operatively connected with said rod, said rod provided at its lower end with a bit engaging head or key.

2. An underreamer comprising a body having a central bore, a rod mounted to reciprocate in said bore, said body and rod provided with slots, a key mounted in said slots, said key having a projection or wing projecting downward from the slot of the body into the central bore and preventing lateral motion of the key, a spring mounted on said key and coiled about said rod, means at the upper end of said rod adjustably connecting said rod and spring, means at the lower end of said rod for engaging and supporting the bits or cutters, and cutters or 3. An underreamer comprising a body having a vcentral bore, a rod or mandrel mounted in said bore, said body and rod provided with registering slots, a key or gib mounted in said slots and having a pro jection or wing fitting wit-hin the bore of said mandrel below said slots and shouldering against the wall upon transverse movement in either direction, a spring mounted on said gib and operatively connected with said rod, said rod provided at its lower end with bit engaging and supporting means, said rod being enlarged at its lower end and provided with surfaces adapted to support the inner ends ofthe bits or cutters, and bits or cutters mounted on said rod.

4. An underreamer comprising a body having a central bore, a rod or mandrel.

mounted in said bore, said body and rod provided with registering slots, a key or gib mounted in said slots, the slot in the rod being of suiicient longitudinal extension to permit the movement of Said rod longitudinally of said body, a keyv or gib loosely mounted in said slots and having a projection or wing projecting downward into the centra-l bore below the walls of the slot in the body and anchoring said key or gib against movement transversely of said body, a spring mounted on said gib and operatively connected with said rod, said'rod provided at its lower end with bit engaging means, bits tiltingly carried thereby, and bearings for the inner faces of said bits formed on said rod and adapted to prevent lateral displacement of said bits.

5. An underreamer comprising a body having a central bore, a rod mounted in said bore, said body and rod provided with registering slots, a key or gib loosely mounted in said slots and having means at the bottom for anchoring in said body, a spring surroundin said rod and connected thereto at the top t ereof, and operatively connected to said key at its lower end, said rod pro-l vided with bit engaging means.

6. An underreamer comprising a body having a central bore, a spring actuatedrod mounted in said bore, said rod provided with bit carrying means, and a key loosely mounted in said body and held therein by the tension of said spring. l

7. An underreamer comprising a hollow body, a spring actuated rod mounted therein and provided with bit carrying means, and a key loosely mounted in said body and operatively connecting said rod and body.

8. An underreamer comprising a hollow body, a reciprocating rod, a spring and a key operatively mounting said rod in said body, said key fitting loosely in said body and held thereinby spring tensiony on the top, and means preventing the key sliding laterally in the body without overcoming the downward pressure of the spring on the key.

my hand at Los Angeles, California, this 12th day of February, 1913.

ROBERT E. BOLE. In presence of- FREDERICK S. LYON, F. A. CRANDALL. s.

In testimony whereof I have hereunto set I 

